A well or spring, particularly a deep well, comprises a vertical, inclined or horizontal well shaft and a tube with perforations. Between the well shaft and the tube natural or artificial filter gravel is arranged. The water which is present in the soil around the well shaft flows through the well shaft, the filter gravel and the perforations in the tube into the well. The water from the well may be supplied to a water supply network.
The water entering through the well shaft carries particles and sediments and or chemical and bacteriological solids. When passing the filter gravel the water is filtered and the particles and sediments etc. accumulate in the filter gravel. The resulting film or layer of sediment in the filter gravel and on the tube walls and on the borehole wall reduces the efficiency of the well. Thus, this film of sediments has to be removed.
Known devices for cleaning wells comprise a body on which nozzles are arranged in a plane. The body is inserted into the well and the nozzles are supplied with a fluid under high pressure. The fluid enters the area of the filter gravel through the perforations in the tube. Due to the high pressure the sediments are removed from the filter gravel and flow into the well together with the fluid. An electrical or engine driven motor may drive the nozzles to rotate around the body.
However, the known devices may have a complicated layout. Furthermore, the known devices have to be manually adjusted for the requirements of the particular well.